This invention relates to improvements in laminated packing materials in the form of a hollow molded article, film or sheet, and more particularly to a laminated packing material wherein one layer of the lamination consists essentially of an acrylonitrile-rich resinous material or comprises an acrylonitrile-rich resinous material, and the other layer consists essentially of a polyolefin or an ethylene-vinyl acetate copolymer, or contains a resinous material comprising a polyolefin or an ethylene-vinyl acetate copolymer.
Although a polyolefin and an ethylene-vinyl acetate copolymer, especially those containing a small quantity of vinyl acetate, have excellent water and moisture proof properties, due to their high permeability to gas such as oxygen, they are not suitable for use as packing materials for foodstuffs, medicines and cosmetics, which are required to have high resistance to gas permeance.